Thursday, July 19, 2018

Autism screening 2

Yuen T, Penner M, Carter MT, Szatmari P, Ungar WJ. Assessing the accuracy of the Modified Checklist for Autism in Toddlers: a systematic review and meta-analysis. Dev Med Child Neurol. 2018 Jul 11 [Epub ahead of print].


The Modified Checklist for Autism in Toddlers (M-CHAT) could be appropriate for universal screening for autism spectrum disorder (ASD) at 18 months and 24 months. Validation studies, however, reported differences in psychometric properties across sample populations. This meta-analysis summarized its accuracy measures and quantified their change in relation to patient and study characteristics.

Four electronic databases (MEDLINE, PsycINFO, CINAHL, and Embase) were searched to identify articles published between January 2001 and May 2016. Bayesian regression models pooled study-specific measures. Meta-regressions covariates were age at screening, study design, and proportion of males.

On the basis of the 13 studies included, the pooled sensitivity was 0.83 (95% credible interval [CI] 0.75-0.90), specificity was 0.51 (95% CI 0.41-0.61), and positive predictive value was 0.53 (95% CI 0.43-0.63) in high-risk children and 0.06 (95% CI <0.01-0.14) in low-risk children. Sensitivity was higher for screening at 30 months compared with 24 months.

Findings indicate that the M-CHAT performs with low to moderate accuracy in identifying ASD among children with developmental concerns, but there was a lack of evidence on its performance in low-risk children or at age 18 months. Clinicians should account for a child's age and presence of developmental concern when interpreting their M-CHAT score.

The Modified Checklist for Autism in Toddlers (M-CHAT) performs with low-to-moderate accuracy in children with developmental concerns. There is limited evidence supporting its use at 18 months or in low-risk children.


An autism screening tool commonly used in toddlers shows low-moderate accuracy in children who have shown developmental signs, according to this meta-analysis.
Clinicians should take age and risk into account when using this screen, the Modified Checklist for Autism in Toddlers (M-CHAT).

Why this matters

Studies assessing the effectiveness of the M-CHAT have had design weaknesses that have left evidence gaps.
These authors say that given their findings, the M-CHAT might be better used as a second-line screening tool, with developmental surveillance foregrounded.

Key results

Pooled results:
Sensitivity: 0.83 (95% credible interval [CrI]), 0.75-0.90); range, 0.64-0.96 in high-risk children.
Specificity: 0.51 (95% CrI, 0.41-0.61); range, 0.27-0.67 in high-risk children.
Positive predictive value (PPV) in high-risk children: 0.53 (95% CrI, 0.43-0.63).
PPV in low-risk children: 0.06 (95% CrI, <0.01-0.14).
Better screening sensitivity in older (30 months; 0.69 [95% CrI, 0.19-0.86]) vs younger (24 months; 0.55 [95% CrI, 0.02-0.84]) toddlers.
All studies had bias risk, including volunteer bias, lack of blinding.
Few studies (n=3) included low-risk children.
Study design

Meta-analysis, systematic review, 13 studies.
Funding: Canadian Institutes of Health Research Autism Research Training Program; others.

Criteria changed in study time frame (January 2001-May 2016).
Limitations of the included studies.


Øien RA, Schjølberg S, Volkmar FR, Shic F, Cicchetti DV, Nordahl-Hansen A, Stenberg N, Hornig M, Havdahl A, Øyen A-S, Ventola P, Susser ES, Eisemann MR, Chawarska K. Clinical Features of Children With Autism Who Passed 18-Month Screening. Pediatrics. 2018 May 21 [Epub ahead of print].


We compared sex-stratified developmental and temperamental profiles at 18 months in children screening negative for autism spectrum disorder (ASD) on the Modified Checklist for Autism in Toddlers (M-CHAT) but later receiving diagnoses of ASD (false-negative group) versus those without later ASD diagnoses (true-negative group).

We included 68 197 screen-negative cases from the Norwegian Mother and Child Cohort Study (49.1% girls). Children were screened by using the 6 critical items of the M-CHAT at 18 months. Groups were compared on domains of the Ages and Stages Questionnaire and the Emotionality Activity Sociability Temperament Survey.

Despite passing M-CHAT screening at 18 months, children in the false-negative group exhibited delays in social, communication, and motor skills compared with the true-negative group. Differences were more pronounced in girls. However, with regard to shyness, boys in the false-negative group were rated as more shy than their true-negative counterparts, but girls in the false-negative group were rated as less shy than their counterparts in the true-negative group.

This is the first study to reveal that children who pass M-CHAT screening at 18 months and are later diagnosed with ASD exhibit delays in core social and communication areas as well as fine motor skills at 18 months. Differences appeared to be more pronounced in girls. With these findings, we underscore the need to enhance the understanding of early markers of ASD in boys and girls, as well as factors affecting parental report on early delays and abnormalities, to improve the sensitivity of screening instruments.


Children missed by a common autism screening tool share some features, including social and communication and fine motor delays.
Girls are more often overlooked.
An editorial accompanies the study.

Why this matters

The Modified Checklist for Autism in Toddlers (M-CHAT) is used at age 18 months.
Earlier developmental windows may be more amenable to mitigating some delays associated with autism.

These authors say that they know of no other such study.

Key results

228/68,197 children with negative M-CHAT later diagnosed with autism.
Only 15.8% of missed children were boys.
Affected domains at age 18 months included:

Social: significant diagnosis-by-sex interaction (P=.001); false-negative boys and girls both rated as “less social” vs true-negative groups (P<.001 and .007, respectively);
Communication: significant diagnosis-by-sex interaction (P=.002); significant communication skills difference for both false-negative boys and girls vs true-negative groups (both P<.001);
Motor: for gross motor, significant diagnosis-by-sex interaction and difference for both false-negative boys and girls vs true-negative groups (P<.001 for all); for fine motor, significant difference for false-negative boys and girls vs true-negative group (P<.001, both).

Study design

Norwegian Mother and Child Cohort.
Funding: Norwegian government; US National Institute of Environmental Health Sciences.


No concurrent direct measures of verbal development.

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